System for conveying an article using vortex suction units

ABSTRACT

A system for conveying an article along a transfer path includes at least a first and a second vortex suction unit disposed in sequence in a direction of the transfer path. A conveyor is configured to support the article relative to at least one of the suction units and a main controller is configured to separately control the vortex suction units so as to convey the article along the transfer path using the conveyor.

CROSS REFERENCE TO PRIOR APPLICATION

This application is a continuation of U.S. patent application Ser. No.12/556,734, filed on Sep. 10, 2009, and which is hereby incorporated byreference herein.

FIELD

The present invention relates generally to conveyance systems, and morespecifically to a system for conveying an article using vortex suctionunits.

BACKGROUND

Conveyance systems ordinarily rely on friction drives (i.e., belts orrollers) using gravity as a friction force to maintain an article beingconveyed along a transfer path. However, when the article beingtransported is relatively flat and/or lightweight, ambient air streamscan cause the article to get blown off from the conveyor. Additionally,when the conveyor is vertical or inclined, the article is likewisesusceptible to sliding, rolling or flying away from the transfer path.

U.S. Pat. No. 5,671,920 describes use of an external low pressuregenerator for providing an additional force to maintain an article on aconveyor.

U.S. Patent Application Publication No. 2005/0133980 describes use of anaxial fan on the opposite side of a belt from paper being conveyedthereon.

U.S. Pat. No. 6,565,321 describes a vortex attractor. An impellerincluding a plurality of radial blades extending in a direction of therotation axis are provided to generate a vortex flow. The vortex flowprovides a central negative low pressure region which can be used toattract an object or maintain the vortex attractor against or at adistance from a surface.

SUMMARY

In an embodiment, the present invention provides a system for conveyingan article along a transfer path including at least a first and a secondvortex suction unit disposed in sequence in a direction of the transferpath. A conveyor is configured to support the article relative to atleast one of the suction units and a main controller is configured toseparately control the vortex suction units so as to convey the articlealong the transfer path using the conveyor.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing and other features of the present invention will be morereadily apparent from the following detailed description and drawings ofillustrative embodiments of the invention in which:

FIG. 1 is a front view of a vortex suction unit in accordance with anembodiment of the present invention;

FIG. 2 is a perspective view of the vortex suction unit of FIG. 1;

FIG. 3 is a schematic view of the fluid flow generated by the vortexsuction unit;

FIG. 4 is a sectional view of the vortex suction unit in a conveyancesystem;

FIG. 5 is a top view of a conveyor using vortex suction units inaccordance with an embodiment of the present invention;

FIG. 6 is a schematic view of a system of conveying an article inaccordance with an embodiment of the present invention;

FIG. 7 is a top view of a vortex suction unit having its own means ofconveyance;

FIG. 8 is a sectional side view of the vortex suction unit of FIG. 7;

FIG. 9 is a top view of the vortex suction unit of FIG. 7 provided withmeans for rotating the unit;

FIG. 10 is a top view of a conveyance system including a plurality ofvortex suction units of FIG. 9 and a controller connected thereto;

FIG. 11 is a schematic view of a conveyance system illustrative of useof the vortex suction units for double-pick handling;

FIG. 12 is a schematic view of a conveyance system having sortingcontainers for the handling of a double-pick;

FIG. 13 is a schematic view of a conveyance system having guides formoving the vortex suction units along the transfer path;

FIG. 14 is a schematic view of a flipping portion of a conveyancesystem;

FIG. 15 is a schematic view illustrating the individual control ofvortex suction units as an article is conveyed along the transfer path;

FIG. 16 is a schematic view illustrating the individual control ofvortex suction units for conveying and sorting the article;

FIG. 17 is a sectional view of a staggered arrangement of vortex suctionunits in a conveyance system;

FIG. 18 is a graph comparing attraction force and power consumption ofvortex suction units and standard axial fans;

FIG. 19 is a schematic view of a controller for first and second vortexsuction units;

FIG. 20 is a schematic view of the controller of FIG. 19 integrated ontothe first vortex suction unit;

FIG. 21 is a schematic view of a controller for first and second vortexsuction units having a shared belt and belt drive;

FIG. 22 is a schematic view of a main controller and modular controllersin accordance with an embodiment of the present invention; and

FIG. 23 is a schematic view of a conveyance system having twomechanical-guide conveyors and vortex suction units in accordance withthe present invention.

Like reference numerals are used in the drawing figures to connote likecomponents of the system.

DETAILED DESCRIPTION

Referring to FIGS. 1-3, a vortex suction unit 10 includes an uppervortex generator 12 driven by a motor 20. The upper vortex generator 12includes a base 18 concentrically driven by the motor 20 and a pluralityof blades 14 radially disposed on the base 18 and extendingperpendicularly upwards therefrom. In an embodiment, a similar lowervortex generator 16 including blades 14 is provided on the opposite sideof the base 18 in order to provide a cooling flow of air to the body ofthe motor 20. However, in one embodiment, only the upper vortexgenerator 12 is provided to generate the attraction force A based uponthe principles of a tornado. The motor 20 may be an AC or DC motor. Forexample, the motor 20 is a brushless DC motor or a stepper motor. Theblades 14 may be a number of different shapes, such as curved. In anembodiment, the blades 14 are substantially straight and flat. Forexample, the blades 14 of the upper vortex generator 12 may include arecessed at an upper, inward and radially-extending portion thereof. Ahousing 30 may be provided on the vortex suction unit 10 surrounding theperipheral edge of the base 18 and blades 14. The housing 30 may be, forexample, a shell or a ring. Alternatively, the upper vortex generator 12and/or the lower vortex generator 16 may be manufactured, for example,by molding, to form a ring surrounding the blades 14.

A vortex suction unit 10 is any device capable of generating a vorticalfluid flow FF. By way of example, a vortex attractor as described inU.S. Pat. No. 6,565,321 or in U.S. Pat. No. 7,204,672, which are herebyincorporated by reference herein, may be used. The radially extendingblades 14 generate the fluid flow FF helically containing a low pressureregion LP within the vortex generator 12 inside the peripheral edges ofthe blades 14. An attraction force A is generated in the low pressureregion LP which allows the vortex suction unit 10 to both attract andmove toward (when the vortex suction unit 10 is not fixed) the surfaceof an object. Vortex suction units 10 are effective to removably adhereto planar and non-planar surfaces or to maintain the same at apredetermined distance. It is also noted that the vortex suction units10 may be modified to apply a negative attraction force A, or arepulsion force, to push an article 50 away.

In one embodiment, the upper and lower vortex generators 12, 16 areformed from a lightweight material, such as plastic, and have a diameterof approximately 50 mm. In this manner, the rotational inertia is keptlow such that the vortex suction module can be started and stoppedquickly. Likewise, the speed may be adjusted quickly and easily. Themotor 20 is a brushless DC motor which responds quickly to changes inpower level to adjust its rotations per minute (rpm). At about 22,000rpm, the vortex suction unit 10 generates an attraction force A of about1.3 N throughout the low pressure region LP. Referring to FIG. 18, acomparison is made for illustrative purposes between a vortex impellerand a vacuum suction chamber having a fan configured for low pressuregeneration (vacuum power). In addition to being responsive to powerchanges to quickly change speed and thereby increase or decrease itsattraction force, the vortex impeller is also far more efficient andeffective than the vacuum system when at a distance from an object to beadhered; this is a desirable positioning for proper conveyance to allowroom for belts and/or prevent sticking. For example, where the article50 is disposed at a distance of 1.0 mm from the upper vortex generator12, an attraction of approximately 0.7 ounces is achieved whileconsuming only about 3.5 Watts of power. In contrast, at the samedistance of 1.0 mm, the fan of the vacuum generator consumesapproximately 6.5 Watts of power while providing attraction for onlyabout 0.1 ounces.

Referring to FIGS. 4-6 and 17, vortex suction units 10 are disposedadjacent a transfer path TP, the direction of which is indicated byarrows. An article 50 is moved by a conveyor 80 along the transfer pathTP by belts 40 and/or fraction rollers 46. The transfer path TPcorresponds to the predetermined conveyance positions of the article 50as it moves along the conveyor 80. The vortex suction units 10 arearranged in sequence along the transfer path TP and may also be disposedinto arrays 70 which may be, for example, vertical arrays 70 a, 70 barranged side by side or sequentially arranged horizontal arrays 70 c,70 d. It is also possible to provide the vortex suction units 10 in anoffset arrangement (see FIG. 17) in order to reduce the total number ofvortex suction units 10 necessary for a particular conveyor 80. Thevortex suction units 10 may be arranged side by side, and may bearranged with a predetermined spacing which is less than the length of arespective edge of the article 50 such that it is adhered to the belts40 at all points during conveyance.

The housings 30 of the vortex suction units 10 may be square or othershapes and surround the outside edges of the blades 14. A cover 32,which may be a screen, a grid, concentric circles, an air permeablematerial, a plate with openings or ribs, may be provided on the vortexsuction units 10. In an embodiment shown in FIG. 7, the cover 32includes ribs extending in the direction of the transfer path TP suchthat an article 50 which is flexible, such as paper, is provided aslight corrugation in the direction of the transfer path TP. The housing30 may also include idler balls or rollers which contact the article 50during conveyance to decrease friction.

The cover 32 may be provided to minimize risk of injury, keep objectsfrom interfering with the blades, to maintain a spacing to the article50 and/or to aid in guiding and supporting the article 50 as it movesalong the transfer path TP. In an embodiment, the cover 32 is disposedat a distance from the article 50 such that a flexible article 50 beingcarried by belts 40 is given a concave or corrugation shape by vortexsuction units 10 positioned between pairs of belts 40, thereby impartinga degree of rigidity. Further, covers 32 may extend between vortexsuction units 10 so as to provide a smooth, supported transition as thearticle moves from one vortex suction unit 10 to the next.

The belts 40 may be formed from a material having a significantcoefficient of friction and may be toothed, such as in a synchronoustype conveyor, textured or profiled. For example, spikes, grooves orribs may be provided on the surface of the belts 40. Typical elastic orelastomeric belts 40 are sufficient to convert the normal force into atransport force. The surface of belts 40 may be roughened to increasefriction in their entirety or only at certain areas to create a surfacehaving regions with different coefficients of friction. Further, thebelts 40 may be at least partially air permeable. For example, the belts40 may be perforated or formed from a nano-material. The belts 40 may bedriven by a belt drive 44, which may be adjustable to control theconveyance speed.

The conveyor 80 may include support rails 48 which support and assist inmaintaining the position of the article 50 in the transfer path TP. Inan embodiment, the vortex suction units 10 are arranged on the oppositeside of the belts 40 from the article 50 and are positioned betweenadjacent pairs of belts 40. However, one air permeable belt 40 may beprovided over in lieu of the covers 32. The belts 40 may also contain aplurality of perforations 42 through which the attraction force Aadheres the articles 50 to the belts 40, in which case the conveyor 80includes just one belt 40 or multiple parallel belts 40.

Other types of conveyors 80 are also possible, such as ones usingsequentially arranged driven rollers with a spacing therebetween, inwhich case the vortex suction units 10 are arranged below the spacingsand provide the attraction force A to the article 50 therethrough.Likewise, conveyors 80 include other systems of conveyance, such assupports, for example, support rods or rollers, arranged such that thearticle is conveyed by gravity or an applied force.

The conveyors 80, may be horizontal conveyors 82, vertical conveyors 84,and may also be inclined, curved, rectangular, circular, or the like.For example, as shown in FIG. 6, an article 50 enters the transfer pathTP on top of a first horizontal conveyor 82 a, traveling to a verticalconveyor 84 and up to the bottom of a second horizontal conveyor 82 b,wherein the attraction force A of the vortex suction units 10 issufficient to hold the article 50 against the belts 40 even in thepresence of a gravitational force downward. In this conveyance system100, the article 50 is both flipped and translated upwards by the designof the transfer path TP. Especially when the article 50 is relativelyflat and flexible, such as paper, deflectors 88 may be provided betweenconveyors 80 that are separated and/or at angles relative to oneanother, such as horizontal and vertical conveyor 82, 84, to direct thearticle 50 onto the respective belts 40 or other conveyance surface.Further, a main controller 60 may be provided to control belt drives 44and vary the conveyance speed of the conveyors 82 a, 82 b, 84 and/or tocontrol the attraction force provided by the vortex suction units 10either individually (separately) or in groups. For example, since thesecond horizontal conveyor 82 b must adhere the article 50 againstgravity, the vortex suction units 10 therein can be driven at a higherspeed than those of the first horizontal conveyor 82 a. Similarly, theattraction force A may be increased when a heavier article 50 enters thetransfer path.

Referring to FIGS. 7-10, each vortex suction unit 10 may be providedwith its own means of conveyance, such as, for example, its own pair ofbelts 40 having perforations 42 that are driven by traction rollers 46connected to a belt drive 44. A cover 32 having ribs is provided on thehousing 30 over the upper vortex generator 12 parallel to the belts 40to provide a slight corrugation to flexible articles 50 in conveyancedirection and to minimize friction as the article 50 moves across thecover 32. In an embodiment, the housing 30 surrounds the upper and lowervortex generators 12, 16, or at least the upper vortex generator 12.Additionally, each vortex suction unit 10 may also be provided with itsown modular controller 62 which is functionally coupled with the motor20 and/or the belt drive 44 to control the speed of the vortex suctionunit 10 and belts 40 by varying power levels provided thereto. Further,each individual modular controller 62 may also be functionally coupledto a main controller 60 which, for example, is able to provide varioussignals to first and second vortex suction units 10 a and 10 b so as tomove their respective motors 20 or belts 40 at different speedsdepending on, for example, the desired attraction force, conveyancespeed, positioning of the article 50 and predetermined transfer path TP.

Each vortex suction unit 10 may also be provided with its own means forrotation, such as a rotation motor 52 connected to a crown gear 54disposed on a rear surface of the vortex suction unit 10. The rotationmotor 52 is attached to a support 56 which is fixed at one end and atthe other end is rotatably connected to the vortex suction unit 10 atthe axis of rotation of the motor 20. The main controller 60, directlythrough control lines 64 or through a modular controller 62, providespower to the rotation motor 52 in order to rotate the crown gear 54 andposition a vortex suction unit 10 at a particular alignment angle α.Further, the angular rotation of individual vortex suction units 10,which may be provided for both vertically and horizontally, can providefor numerous different, complex transfer paths TP in three-dimensions,and also allows for quick adjustments in transfer paths TP and forchanges in alignment of articles 50 therein. For example, such rotatablevortex suction units 10 could be rotated before and or while holding anarticle 50 to distribute it to various conveyors 80 or belts 40 of othervortex suction units 10 disposed horizontally at angles to its own belts40 and/or positioned vertically above or below.

Additionally, vortex suction units 10 provided with individual beltsand/or rotation means may be used to align an article 50, for example,to an alignment edge 58 of a conveyor 80. The vortex suction units 10are rotated to or disposed at an alignment angle α directed toward thealignment edge 58 to translate an article 50 from its position at aninput traction rollers 46 a and align it to the alignment edge 58 beforeexiting through the output traction rollers 46 b. Alternatively oradditionally, one row of vortex suction units 10 could be part of afirst array 70 a and a parallel row of vortex suction units 10 could bepart of a second array 70 b. In such a case, the controller 60 would beable to rotate the vortex suction units 10 of the first array 70 a tothe alignment angle α and/or drive their belts 40 at higher speeds thanthose of the vortex suction units 10 of the second array 70 b to alignthe articles 50.

Referring to FIGS. 11 and 12, examples of conveyance systems 100 usingvortex suction units 10 to handle double-picks, or multiple overlappingarticles in the transfer path, are shown. First and second arrays 70 a,70 b are arranged in parallel and facing one another. Referring to FIG.11, as overlapping first and second articles 50 a, 50 b travel upwardsalong the transfer path TP on the vertical conveyor 84, the secondarticle 50 b will start to peel away from the first article 50 a. An airknife 90 may provide a tangential air stream to facilitate theseparation of the first and second articles 50 a, 50 b. The vortexsuction units 10 of the first and second arrays 70 a, 70 b may beprovided an increasing or decreasing attraction force A in the directionof the transfer path P. For example, the vortex suction units 10 at thelower end of the first array 70 a may have a smaller attraction force Ato ensure that an overlapping second article 50 b will start to separatefrom the first article 50 a. Additionally, as the second article 50 bnears the vortex suction units 10 of the second array 70 b, the air flowwill become hindered, causing current to decrease and rpm to increase,at which point additional power may be provided to one or more of thevortex suction units of the second array. The conveyance system 100 ofFIG. 12 is similar to that of FIG. 11, except that gravitational forceaids in the separation of the second article 50 b and that a stackingcontainer 94 and a double-pick container 92 are provided for sortingfirst and second articles 50 a, 50 b, respectively. Further, the vortexsuction units 10 above the stacking container may be sequentially slowedand/or disengaged so as to provide a gradual release of the article 50.

Referring to FIG. 13, a conveyor 80 includes vortex suction units 10which adhere to the articles 50 and move them along the transfer pathTP. The vortex suction units 10 are mechanically and/or electricallyconnected to a guide 38 which travels in the direction of the transferpath TP. The guide 38 may be belts 40 or other conveyance means formoving the vortex suction units 10 in the direction of the transfer pathTP. For example, a belt drive 44 can be used to drive one or moretraction rollers 46 moving one or more belts 40 to which the vortexsuction units 10 are attached. Additionally, the traction rollers 46 andthe inside surfaces of the belts 40 may each be formed from a conductivematerial and electrically connected to the vortex suction units 10 torout power thereto from a controller 60 or power source. The controller60 may also be used to drive the belt drive 44 at various speeds and/orto adjust the power level at individual vortex suction units 10. Whilethe conveyor 80 shown in FIG. 13 is an elevator conveyor which flips anarticle 50 from input I to output O, movable vortex suction units 10traveling with or along a guide 38 in the direction of the transfer pathTP may be provided in any type of conveyance system 100 alone or incombination with stationary vortex suction units 10.

Referring to FIG. 14, a conveyance system 100 which is also effectivefor flipping an article 50 provides the article 50 through a deflector88 and input roller 46 a to a horizontal conveyor 82 having vortexsuction units 10. The article is then directed to an inclined conveyor83 after being flipped by a deflector 88 having a radius of curvature r.The inclined conveyor 83 then carries the flipped article out throughoutput roller 46 b. A controller 60 may be provided to control therespective belt speeds of conveyors 82, 83 and the speed of each oftheir respective vortex suction units 10.

Referring to FIG. 23, a conveyance system 100 having first and secondconveying devices 80 a, 80 b with first and second vortex suction units10 a, 10 b, is shown. As an article 50 moves along the transfer path TPbetween the first and second vortex suction units 10 a, 10 b, the maincontroller 60 selectively engages a respective one of the first andsecond suction units 10 a, 10 b to adhere the article 50 thereto. In theembodiment shown, the first conveying device 80 a is a mechanical-guideconveyor which moves the first vortex suction unit 10 a along a firstsecondary path TP1 extending from Position A1 in the transfer path TP toPosition A2 at a first stacking container 94 a. The second conveyingdevice 80 b is likewise a mechanical-guide conveyor which moves thesecond vortex suction unit 10 b along a second secondary path TP2extending from Position B1 in the transfer path TP to Position B2 at asecond stacking container 94 b. Mechanical-guide conveyors may userollers 112 movable along rails 114 and/or drive gears 116 meshing withteeth 118. Further, the rollers 112 or the drive gears 116 connectedwith the vortex suction units 10 may also be coupled with the beltdrives 44 thereof, or could be directly connected to the controller 60,to control speed and direction. Likewise, the first and second conveyingdevices 80 a, 80 b may utilize belts 40 respectively attached to thefirst and second vortex suction units 10 a, 10 b as in FIG. 13, whichare bidirectional.

For example, where the article 50 is printed paper, it is adhered toeither the first vortex suction unit 10 a or the second vortex suctionunit 10 b depending on which side of the paper contains ink. When afirst article 50 a has printing on a first side, the controller 60switches on or speeds up the first vortex suction unit 10 a which thentravels along the first secondary path TP1 to the first stackingcontainer 94 a, into which the first article 50 a is dropped once theink has dried. Similarly, when a second article 50 b is printed on theopposite side, the controller 60 switches on or speeds up the secondvortex suction unit 10 b which then travels along the second secondarypath TP2 to the second stacking container 94 b, into which the secondarticle 50 b is dropped once the ink has dried.

FIGS. 15 and 16 are schematic representations of different controlschemes which may be provided to individual vortex suction units 10 of aconveyance system 100 through a main controller 60. The controller 60may control individual vortex suction units 10 separately or in groups.When an article 50 is positioned in the low pressure region LP of avortex suction unit 10, the air flow is hindered causing the current (i)to decrease and the speed (rpm) to increase compared to idle conditions.Thus, the current level and/or speed may be used as an indicator that asubstrate is present adjacent a vortex suction unit 10, in other words,that a low pressure condition exists. Since the vortex suction unit 10-Ais not covered by an article 50 as indicated to the controller 60 by arelatively high current and low speed, it may be switched off. Vortexsuction units 10-B and 10-C are actively maintained in operation by thecontroller 60 since the article 50 is hindering air flow and causing thecontroller 60 to recognize a relatively low current and high speed.Further, the controller 60 recognizes that the subsequently arrangedvortex suction unit 10-D will need to be switched on as it is next inthe sequence. Once the article 50 is covering the vortex suction unit10-D, vortex suction unit 10-B can be switched off and so on. The timingof such provident triggering of sequentially arranged vortex suctionunits 10-A through E by the controller 60 may be determined inaccordance with a predetermined conveyance speed, the speed at which thecontroller 60 drives belts 40 and/or by relative changes in current orspeed as the article 50 moves past individual vortex suction units 10.Because vortex suction units 10 are relatively small and lightweight,they may be shut off and activated relatively quickly. Thus, aconsistent adherence may be applied efficiently since only vortexsuction units 10 carrying an article 50 are active.

Alternatively or additionally, the controller 60 may provide differentpower levels to the motors 20 of the sequentially arranged vortexsuction units 10-A through E so as to drive them at different speeds andthereby provide various magnitudes of an attraction force A. Forexample, the controller 60 could provide decreasing speeds to thesequentially arranged vortex suction units 10-A through E carrying anarticle 50 along a transfer path TP against the force of gravity.Heavier articles 50 will fall away sooner than lighter articles 50because of the decreasing attraction force A. Thus, a sorting functionmay be obtained using deflectors 88 or sorting bins arranged in sequenceto capture different articles 50 a, 50 b, 50 c of various type, weightand/or size.

Referring to FIGS. 19-22, the controller 60 for at least first andsecond vortex suction units 10 a, 10 b may be provided externally (FIGS.19 and 21) or with one of the vortex suction units 10 (FIG. 20). Thecontroller 60 provides power to the vortex suction units 10 eitherdirectly or through a modular controller 62 and senses current andspeed. Additionally, the controller 60 may also power the belts 40,which may be common (FIG. 21) or provided for each vortex suction unit10 (FIGS. 19 and 20), and control the direction thereof by switching therotation of the belt drive 44.

A control system 110 includes a main controller 60, and optionallyincludes modular controllers 62 for individual vortex suction units 10.The main controller 60 and the modular controllers 62 may include one ormore sub-controllers 66, which may be, for example microcontroller ModelNo. ATMEGA88P manufactured by ATMEL Corp. Further, the main controller60 and the modular controllers 62 may include communication interfaces67 connected through control lines 64 for data exchange. Thecommunication interfaces 67 may be, for example, Control Area Network(CAN) controllers Model No. MCP2515 manufactured by Microchip TechnologyInc. which communicate with the controllers 60, 62 through a standardSerial Peripheral Interface (SPI) and the control lines 64 may be a CANbus system or a communication system using the RS-485 communicationstandard.

The main controller 60, which may be, for example, controller Model No.AT90CAN128 manufactured by ATMEL Corp., is provided to control the speedof belt drives 44, rotation motors 52 and/or the motors 20 of individualsuction units 10 either directly or through modular controllers 62. Themodular controllers 62 may include motor controllers 68 which may be,for example, control chip Model No. NJM 2673 manufactured by New JapanRadio Co., Ltd. for stepper motors or control chip Model No.EBL-H-50-03-05 manufactured by Portescap for brushless DC motors. In anembodiment, the belt drives 44 and the rotation motors 52 are steppermotors and the motors 20 are brushless DC motors. Further, sensors 65may be provided for measuring the speed (rpm) of the belt drive 44,rotation motor 52 and/or motor 20, and for transmitting such data as anencoded signal to the main controller 60 either directly or through themodular controllers 62. Other configurations of the control system 110,however, are also possible. For example, where the modular controllers62 are not provided the motor controllers 68 may be provided with themain controller 60 or on individual suction units 10.

The articles 50 may be flat, flexible articles, such as paper or plasticsheets. However, other types of articles, such as boxes or containers ofvarious shape may be carried by conveyance systems 100 using vortexsuction units 10 according to the present invention.

While the invention has been particularly shown and described withreference to preferred embodiments thereof, it will be understood bythose skilled in the art that various changes in form and details may bemade therein without departing from the spirit and scope of theinvention. Accordingly, the invention is to be limited only by the scopeof the claims and their equivalents.

What is claimed is:
 1. A method of conveying an article along a transfer path comprising: disposing at least a first and a second vortex suction unit in sequence in a direction of the transfer path; supporting the article relative to at least one of the vortex suction units using a conveyor; determining a position of the article relative to the vortex suction units, using a controller, based on an air flow of at least one of the first and second vortex suction units being hindered by the position of the article relative to the vortex suction units; controlling the vortex suction units so as to convey the article using the conveyor.
 2. The method according to claim 1, further comprising disposing third and fourth vortex suction units in sequence in the direction of the transfer path, wherein the first and third vortex suction units are controlled together as a first array and the second and fourth vortex suction units are controlled together as a second array.
 3. The method according to claim 1, wherein the controlling includes sequentially operating each vortex suction unit along the transfer path based on the determined positions of the article as the article moves along the transfer path.
 4. The method according to claim 1, wherein the controlling is performed so as to control at least one of a speed of the conveying, a direction of the conveying, and an attraction force of the article to the conveyor.
 5. The method according to claim 1, wherein the determining the position of the article includes determining, by the controller, at least one of a speed and a current of at least one of the first and second vortex suction modules.
 6. The method according to claim 1, wherein the controlling includes a provident triggering of sequentially arranged vortex suction units along the transfer path based on relative changes in at least one of a speed and a current of the sequentially arranged vortex suction units.
 7. The method according to claim 1, further comprising aligning the article to an alignment edge using at least one of different belt speeds of the conveying devices and a rotation of at least one of the vortex suction units.
 8. The method according to claim 1, wherein the determining the position of the article is performed without using an external sensor.
 9. The method according to claim 1, wherein the determining the position of the article is performed by the controller measuring at least one of a speed and a current of the vortex suction modules.
 10. The method according to claim 9, wherein the controlling is performed by the controller separately operating the vortex suction modules sequentially along the transfer path.
 11. The method according to claim 1, further comprising operating the first and second vortex suction modules at different speeds.
 12. The method according to claim 1, wherein the determining the position of the article further comprises using the controller to determine whether the air flow of a third vortex suction unit, disposed sequentially along the transfer path after the first and second vortex suction units, is also being hindered by the position of the article. 